The metabolic pathways of chemical carcinogens, generally various aromatic amines, are studied both in animals or in isolated tissues. Metabolites are separated by various techniques such as thin-layer, column, gas-liquid, or high-pressure liquid chromatography. Identification is made through physico-chemical means such as mass spectrometry, nuclear magnetic resonance and ultraviolet spectra. Interaction of metabolites with cellular constituents is determined. The effect inhibitors or promoters of the carcinogens exhibit on the metabolic patterns is studied.